Hoisting-machine



(Ho Model.) v

H. J. REEDY,

Hoisting Machine. N0. 235,649. Patented Dec. 21, I880.

PATENT HENRY J. REEDY, OF OINGINNATI, OHIO.

HOISTING -MACHINE.

SPECIFICATION forming part of Letters Patent No. 235,649, dated December 21, 1880.

Application filed October 18, 1880.

To all whom it may concern Be it known that I, HENRY J. REEDY, of Cincinnati, in the county of Hamilton and State of Ohio, have invented certain new and useful Improvements in Hoisting-Machines, of which the following is a specification.

My invention relates to that class of hoisting-machines which are driven by open and crossed belts to produce the elevation and descent of the platform, the power of the belts being transmitted to the lifting-rope by means of the usual worm and worm-gear and winding-drum keyed to the worm-gear shaft, and has for its object the construction and arrangement of the worm on the worm-shaft in such a manner that While the connection of the worm with the Wormshaft will be positive during the elevation of the platform the connection of the worm with the worm-shaft during the descent of the platform will be negative, and should any stoppage of the platform occur during its descent the worm will promptly disengage itself from the driving-connection on the worm-shaft and permit the shaft to re volve freely within it, whereby the worm-gear and winding-drum will remain stationary, and the dangerous consequences of uncoiling the lifting-rope on the winding-drum with the cage suspended in the hoist'will be entirely avoided. Experience has shown the majority of accidents with this class of elevators to occur during the descent of the cage or platform. The sticking of the cage in its grooves or between the rails produces a stoppage in the descent. Meanwhile, the worm-gear being rigidly secured to the worm-shaft, the windingdrum continues to revolve in a backward direction, the lifting-rope uncoilin g and hanging slack. When from any cause the cage orplatform I is relieved down it falls, and usually breaks the lifting-rope, precipitating itself and contents to the bottom of the hoist.

My invention consists in loosely tit-tin g the worm to the worm-shaft to revolve freely thereon as a sleeve, and rigidly securing to the worm-shaft a driving-connection with which the worm engages, and by which it is driven during the ascent of the platform or cage and during the descent of the cage or platform, so long as the lifting-rope is strained by the descending load. Whenever the strain is re- (No model.)

moved from the lifting-rope the worm backs off and disengages from the driving-connection, thereby preventing the continued motion ofthe winding-drum and permitting the wormshaft to revolve freely within the worm without actuating the worm, worm-gear, windingdrum, or lifting-rope.

\Vhen matching teeth or cogs are provided upon the collar and worm they are preferably of the ratchet form.

In the accompanying drawings, Figure l is a side elevation of the hoisting device referred to, with a portion of the housing or worm and worm-gear case removed to show the internal construction. Fig. 2 is an end elevation of the same. Fig. 3 shows themethod of connecting the worm and collar by means of ratchet-teeth. Fig. 4 is a detached view of the driving-collar. Fig. 5 is a detached section of collar and worm.

Similar letters of reference indicate similar parts.

Ais the customary lifting-rope, coiled around and secured to the winding-drum B, which is, in turn, keyed or otherwise secured to the wormgear shaft 0. D is the worm-gear, of the usual form,rigidly secured to the shaft 0. E is the housing or worm and worm-gear case, provided with the ordinary form of bearings e e for the shaft 0. Fis the outboard hanger and bearing for the shaft 0. Gris the usual wormshaft, upon which are mounted the loose pulleys H H and fast pulley I. J is the outboard hanger and bearing for shaft G. K and K are followers or flanged bosses fitted and secured to the housing E to form bearings for the shaft G. The followerKis provided with a tempering-screw, 7t, and steel die 7c, against which the thrust of the worm-shaft G is taken.

L is the worm, of the usual form, bored to turn freely upon the shaft G, and faced upon the end next to the collar M. The collar Mis secured to the shaft by means of the pin m, or in any other suitable manner, and is provided with recesses or holes at .m for the reception of the projecting pins 1 l in the end of the Worm L. In Fig. 3 I have shown the worm Land collarMfurnished with ratchet-teeth 1 ll and m m m.

The action of the device is as foilows: In raising the platform or cage of the elevator the Worm-wheel D and lifting-rope A have a motion in the direction of the arrows, Fig. 1, and the worm a motion from right to left, as shown by the arrow in Fig. 2. Now, it will be obvious that so long as the motion of the wormshaft and worm is in the direction to raise the platform the abutting faces of the worm L and collar M will be held in forcible contact and the worm L caused to revolve with the collar M by means of the engagementof the pins It with the holes m m in the collar M, or by means of the ratchet-teeth Z Z land m m m; but when the motion of the lifting-rope A, winding-drum B, worm-gear D, and collar M is in an opposite direction to lower the cage or platform of the elevator, the worm M would obviously back off from the connection with the driving-collar M unless some means existed to maintain the contact of the collar and worm. This means is found in the weight of platform and load on rope A, which forces the worm L into contact with the collar M and causes the worm and collar to revolve together; but directly the strain upon the lifting-rope A is removed the worm will back out of contact with the collar M and stand idly in position upon the shaft G, and when the strain is reapplied to the rope A the worm will be instantly forced in contact with the collarM and revolve with the collar, as already explained.

In former devices for the stoppage and starting of the windingdrum when the strain is removed from and applied to the rope A the effect is had by engaging and disengaging pawls from ratchets on the rim of the windingdrum and upon parallel disks keyed to the winding-drum shaft; but these devices require a considerable slack of rope to work at all, and are of such a form as to fail at critical moments and permit the very accident they are sought to avoid.

In my device (omitting the breakage of the worm or collar) failure to promptly arrest the slacking of the rope when the strain is removed, or of the worm to re-engage with the collar when the strain upon the rope is reap- 5 plied, is absolutely impossible.

I have shown but two pins in the worm L and two holes in the collar M; butitis obvious that the number of pins and holes may be more or less than two, and that the teeth on 5 the abutting faces of the worm and collar may be of any number or form, without departing from the principle of my invention.

Having described my invention, what I claim is 5 1. [n a hoisting-machine, the combination of a drum on which the lifting-rope is wound, a worm-wheel arranged on the shaft of the drum, a rotating and longitudinally-sliding worm, a horizontal shaft on which said worm 60 is arranged, and mechanism, substantially as described, for connecting and disconnecting the worm and shaft by the action of the lifting-rope and drum, essentially as and for the purpose set forth. 6 2. The combination, with the drum, its shaft, and the lifting-rope of a hoisting-machine, of the worm-wheel D, the horizontal worm-shaft G, having the collar M, provided with holes or teeth at, and the worm L, having pins or 70 teeth Z, and adapted to be moved longitudinally by the action of the lifting-rope and drum to cause it to engage the collar of the worm-shaft, substantially as described.

In testimony whereofI have signed my name 7 to theforegoing specification in the presence of two subscribing witnesses.

HENRY J. REEDY.

Witnesses:

JOHN W. HILL, EDGAR J. Guess. 

